GT2871 USERS. SR motor

[codyace]

Originally Posted by purekoryo

I used to have S3 cams on my old sentra with SR20DET. Does the JWT S3 cams drop right into the S13 SR20DET motors, or does the cams need to be modified a bit? specifically the dowel pin at the end of the cams. Did you have to get the JWT S3M cams?

You don't need the longer dowell pin at all for it to work as it should.

BE careful with the M cams, as they IIRC are for the GTiR solid valvetrain.

Originally Posted by usdm180sx

damn, you got it backwards TWICE.

.64 trim = s3 cams
.86 trim = s4 cams

That's my look at things too.

Originally Posted by purekoryo

Have you tried both setups? You act like you did, and if you did and thought it was pretty bad, than that's great, I know now. But if you didn't I wouldn't say anything if I were you. At least I'm gonna try and see how that works out, as many people that do have JWT cams here go with S3's. As a matter of fact, many MANY sentra guys have sold S3's and bought S4's and never turned back. used S4's are hard to come by in sr20forum, but not S3's. As codyace mentioned they are easier to catch, and even used S4's are a bit more expensive than S3's for a reason. Many guys with the sentras run S4's in conjunction with T25 and T28 turbos all day. The guys with the T28's did not have any noticeable loss in power or lag with S4's.

The main thing i look at with t25/t28 guys, is that they typically aren't making enough power to really show the difference between the two. That, combined with lightning fast small turbo spool, also sorta/kinda leave it up to debate for me.

FWIW: There are a few Japanese tuners that swear by running smaller based turbos with BIG duration (we're talking 266-272) cams and seeing some interesting power (first example is the Mines car, as well as some of the Evo Time Attack cars we see in the JDMyo! kinda videos). Obviously it's hard to compare a little inline 4 to a a little inline 6, but it would be neat to see a side by side comparison from persay, the S3 camshaft to the s4, or to somethign like a 272 duration cam.

Experience says that the larger duration cams will increase spool, but it would be neat to see by how much with the 2871 turbocharger.

Originally Posted by Ninjabread

so the consensus is basically that the .86ar sucks?

Damn, I was just about to buy one

It doesn't 'suck', it's just that (IMO) there are better routes to take. For those that argue 'you'll want the extra 20 whp'....no freaking way. 20 hp isn't even getting your toes wet in the pool. I say, if you want 400 whp, get the .64 housing...anything more, look ta a 3071/3076 variant.

Originally Posted by anyotherone

No, just figure out what you want more - topend or midrange

In my case I had the Full Race turbo manifold and my .86ar spooled more like a .64 so I got the best of both worlds.

The tubular manifold typically spools smalelr turbos later, due to design, and lack of heat retention.

"Good" or "best" are relative terms in this sort of decision. Are you going to drift? Autocross? Street daily driven? Drag or highway race?

I drove my car 95% street and 5% drag, so I went to the .86ar but used cams with better mid range to create a combo that I was really happy with.

This is the ebst way to look at things. I laugh at people that build 'drag' or 'drift' or 'grip' cars, and then take it their respective events twice a year, and are forced to drive a finnicky quasi-race car around the rest of the time. This is exactly why I went with the combo I did. It's perfect for a street car, and just so happens to work awesome on the road course. Don't get me wrong, I know where i could take away/add form the setup, but it's not worth the small changes to sacrifice it's street manners.

Originally Posted by Inlandsilvia

Finally got my S14 tuned right and making power. I am running the following mods:

GT2871R .64 /HKS actuator
1.1 Apexi HG
264 BC cams
BC Valve springs/retainers
Megan mainfold
Megan turbo elbow
Megan downpipe
Megan test pipe
Uras 3" exhaust
Greddy FMIC
NO BOV
Apexi PFC
740cc
Sard FPR
Greddy E01

At 1.1 bar my car was putting down 330hp/301tq.

So arond 16 psi...you should be seeing more in the 350/360 range if you were on a dynojet dyno.

[purekoryo]

Originally Posted by codyace

You don't need the longer dowell pin at all for it to work as it should.

BE careful with the M cams, as they IIRC are for the GTiR solid valvetrain.



That's my look at things too.



The main thing i look at with t25/t28 guys, is that they typically aren't making enough power to really show the difference between the two. That, combined with lightning fast small turbo spool, also sorta/kinda leave it up to debate for me.

FWIW: There are a few Japanese tuners that swear by running smaller based turbos with BIG duration (we're talking 266-272) cams and seeing some interesting power (first example is the Mines car, as well as some of the Evo Time Attack cars we see in the JDMyo! kinda videos). Obviously it's hard to compare a little inline 4 to a a little inline 6, but it would be neat to see a side by side comparison from persay, the S3 camshaft to the s4, or to somethign like a 272 duration cam.

Experience says that the larger duration cams will increase spool, but it would be neat to see by how much with the 2871 turbocharger.




It doesn't 'suck', it's just that (IMO) there are better routes to take. For those that argue 'you'll want the extra 20 whp'....no freaking way. 20 hp isn't even getting your toes wet in the pool. I say, if you want 400 whp, get the .64 housing...anything more, look ta a 3071/3076 variant.




The tubular manifold typically spools smalelr turbos later, due to design, and lack of heat retention.



This is the ebst way to look at things. I laugh at people that build 'drag' or 'drift' or 'grip' cars, and then take it their respective events twice a year, and are forced to drive a finnicky quasi-race car around the rest of the time. This is exactly why I went with the combo I did. It's perfect for a street car, and just so happens to work awesome on the road course. Don't get me wrong, I know where i could take away/add form the setup, but it's not worth the small changes to sacrifice it's street manners.



So arond 16 psi...you should be seeing more in the 350/360 range if you were on a dynojet dyno.

??? But you wanted to get C1's, that really contradicts your statement. Eitherway, I will post my experience with the S4's once its installed. Unfortunately I dont have back to back dyno results, but I did have a GT2871r .86 with S3 cams before and the spool was pretty bad. So far the GT2871r with .64 housing spools really nicely.
SCC did some comparisions of the JWT cams...



scc cam comparo link (please make this a sticky!) - Page 2 - SR20 Forum
NEW JWT S4 SCC REVIEW - SR20 Forum

S4 cams really does not lose much if any low end, just gains more midrange and high end than the S3's.

[steve shadows]

Originally Posted by codyace

So arond 16 psi...you should be seeing more in the 350/360 range if you were on a dynojet dyno.

I think INLANDS #s are on a dynojet or hub dyno, so it would be lower on a Brake eddy Chassis dyno.